1. Field of the Invention
The present invention relates to an image processing method and apparatus having a plurality of image processing sections for performing predetermined image processing on input image data and for outputting the image data.
2. Description of Related Art
Digital multifunction machines (multifunction peripherals, hereinafter referred to as “MFPs”) combining the functions of a copier, a fax, a printer, etc., are widely used. In the MFPs, input/output operations by a scanner section, a printer section, etc., the operation of a function for connecting to a network and a communication line, and the function of image processing of image data, as well as operations in which those are combined, are controlled by a control section (CPU) for controlling the entire system.
An MFP typically comprises an image processing section having several image processing (IP) functions for performing various image processing, such as, for example, resolution conversion, binarization, rotation processing, and color conversion, on input image data. For example, in a copier disclosed in Laid-Open Japanese Patent No. 4-1771, an image processing section is disclosed in which each of these functions is realized as an image processing circuit, and each circuit is connected in series so as to perform pipeline processing on the image data. The system controller (CPU) of this copier is capable of performing settings for image processing in each image processing circuit and performing data transfer instructions thereto via a bus line, and thus is capable of performing desired image processing for each area of an image.
Meanwhile, in recent years, MFSPs have appeared in which concurrent multifunction operation is made possible such that, in addition to simply combining a plurality of device functions so as to operate in sequence, for example, while a fax operation is being performed, a copying operation can be performed. By using, as an example, a case where a copying operation is performed while a fax transmission operation is being performed, a conventional concurrent multifunction operation is described. Here, it is assumed that an image processing section of the MFP is constructed so as to perform pipeline processing by a plurality of image processing circuits, as described in the conventional art. It is also assumed that image data for the fax operation and image data for the copying operation, input by a scanner section, are temporarily stored in a memory in page units.
First, the MFP starts image processing on image data for fax transmission. The CPU performs image processing settings for fax transmission in each image processing circuit within the image processing section via a bus line, etc. Examples of settings include image processing information (resolution, binarization processing method, angle of rotation, paper size, etc.) in each image processing circuit (circuit having resolution conversion function, binarization function, rotation function, etc.). After setting these pieces of image processing information, image data for fax transmission is transferred from the memory to the image processing section, and image processing is performed in sequence for each area in the image data. Then, when image processing for one page of the image data for fax transmission is completed, image processing is started on the image data for the copying operation. The CPU sets image processing information in the image processing section in order to perform image processing. After the setting, the image data is transferred to the image processing section, and in a similar manner, image processing for one page is performed.
In this manner, conventionally, device function operations of the scanner section, the printer section, and the fax function section are concurrently performed in parallel. However, the image processing performed by the image processing section is only processing for each device function operation, which is switched in page units and is performed. That is, a concurrent multifunction operation is not performed in the image processing section, and as is conventionally done, the memory is allocated in page units and the image data is processed in page units. Therefore, it cannot be said that the memory is used effectively, and it cannot be said that efficiency is satisfactory from the viewpoint of performing image processing.
Accordingly, an image processing apparatus has been conceived in which image data in page units is divided in advance into areas having a predetermined size before image processing is performed, and processing is performed in units of the divided area image data. For example, since an image processing section having a construction for performing the above-described pipeline processing can perform image processing for each desired area, image processing in units of the divided area image data can be easily performed. As a result of forming the image processing section in this manner, it is possible to use the memory in units of the area image data.
In addition, since image data for a plurality of device function operations is input in units of the area image data, image processing can be performed in parallel. For example, inside the image processing section, parallel processing can be performed such that while resolution conversion is being performed on the image data related to the fax communication operation, a rotation operation is performed on the image data related to the copying operation.
However, since image data in page units is divided into a plurality of area image data, the number of pieces of image data to be processed becomes enormous. Furthermore, image data for the object of a different image processing operation coexists inside the image processing section. Therefore, in a case where setting for status recognition and image processing of the image processing section, and image data transfer control, using a bus line, etc., which is conventionally performed, are performed, the amount of management information to be processed becomes enormous. As a result, a problem arises in that it is difficult for the CPU which controls the entire system to manage the image processing section.
Furthermore, in a case in which the number of pages to be processed at a time is increased without being limited to performing a concurrent multifunction operation, the number of pieces of area image data, the amount of management information, etc., become enormous. In a similar manner, a problem arises in that it is difficult for the CPU which controls the entire system to manage the image processing section.